Conventional growth of crystals from silicon carbide is achieved by Physical Vapor Transport (PVT) and Physical Vapor Deposition (PVD) which are also applicable to mass production of chips. For example, U.S. Pat. No. 5,746,827 discloses a method of growing large-size crystals from silicon carbide by PVT.
Furthermore, a photonic crystal exhibits periodic changes in material refractive index or dielectric constant in two-dimensional or three-dimensional space to simulate arrangement of atoms in a solid-state crystal. Hence, as regards related prior art, Taiwan patents 1318418 and U.S. Pat. No. 8,384,988 disclose growing a crystal in a two-dimensional manner to build a three-dimensional structure at the expense of restricting the photonic crystal to two-dimensional transmission. Due to the difficulty in a manufacturing process, three-dimensional photonic crystals lag behind two-dimensional photonic crystals in terms of technological advancement. There are few research conducted on three-dimensional crystal manufacturing techniques in Taiwan and the United States, because the prior art renders it difficult to deposit different types of atoms alternately to form multilayer structure. For instance, U.S. Pat. No. 8,384,988 discloses controlling the deposition of atoms in electrochemical and voltage-driven manner. Both U.S. Pat. No. 8,309,113 and U.S. Pat. No. 7,799,378 disclose that substance or polymeric material micoparticles, which can be etched and removed, serve as the fillers between different media to undergo a multilayer stacking process and eventually form a three-dimensional structure. Both U.S. Pat. No. 7,990,611 and U.S. Pat. No. 7,919,216 disclose making photonic crystals by an optical means. U.S. Pat. No. 7,990,611 discloses bringing about an interference pattern by laser-based optical diffraction to thereby produce a periodic structure required for photonic crystals. U.S. Pat. No. 7,919,216 discloses effectuating a periodic structure having the same photonic crystal as a mask. As indicated above, photonic crystal materials are manufactured by an electrochemical means, etching, optical exposure and development, and a semiconductor process, that is, a simple process characterized by easy processing and etching, thereby imposing limitations upon the choice of materials which photonic crystals are made from.